C++ object in QML: "Can't find variable:"

wspilot

Hi,
A have a simple progr to tests QtWidget-C++ QML communication.
QML component shows well , but the C++ object, named "myObject0" for QML is not found:
"ReferenceError: Can't find variable: myObject0"

@int main(int argc, char *argv[])
{
QApplication app(argc, argv);

MainWindow mainWindow;
test0 tt0;
tt0.cppSlot(9999);//works ok
QDeclarativeEngine* engine = new QDeclarativeEngine;
QDeclarativeContext *context = new QDeclarativeContext(engine->rootContext());
context->setContextProperty("myObject0", &tt0);

QDeclarativeComponent component(engine, QUrl::fromLocalFile&#40;"../qml1/test0.qml"&#41;);//Creates a COMPONENT from the given fileName and give it the specified parent and engine.
QObject *object = component.create();//Create an object instance from this component
QGraphicsObject *graphicsObject = qobject_cast<QGraphicsObject *>(object);

qDebug() << component.errors();
graphicsObject->setProperty("width", 300);//works ok
Scene0 scene0;
scene0.setItemIndexMethod(QGraphicsScene::NoIndex);
mainWindow.grahicsView->setOptimizationFlags(QGraphicsView::DontSavePainterState);
mainWindow.grahicsView->setViewportUpdateMode(QGraphicsView::BoundingRectViewportUpdate);
mainWindow.grahicsView->setScene(&scene0);
mainWindow.grahicsView->show();

QVariant returnedValue;
QVariant msg = "text";
QMetaObject::invokeMethod(object, "test0", Q_RETURN_ARG(QVariant, returnedValue), Q_ARG(QVariant, msg));//works ok
qDebug() << returnedValue.toString();

...
}
@
test0.qml:
@Item
{
function test0(msg)//works ok
{
console.log(msg)
helloText.text = msg
}

Rectangle
{
id: rectangle1
width: 300
height: 600
color: "red"
radius: 14
Text
{
id: helloText
text: "HW"
y: 36
}
MouseArea
{
anchors.fill: parent
clip: false
smooth: false
hoverEnabled: true
onClicked: {myObject0.cppSlot(123456)}
}
}
}
@
test0.h:
@class test0 : public QObject
{
Q_OBJECT
public:
explicit test0(QObject *parent = 0);
public slots:
void cppSlot(int number);

};@

coyotte508

change @QDeclarativeContext *context = new QDeclarativeContext(engine->rootContext());@ to @QDeclarativeContext *context = engine->rootContext();@

Also try before everything else to add:

@qmlRegisterType<test0>();@

Also, it's a good idea to have your class names (here test0) start by uppercase (Test0).

wspilot

Thanks al lot. You saved my day!
I took my code from the documentation "QDeclarativeContext Class Reference":http://qt-project.org/doc/qt-4.8/QDeclarativeContext.html.